Sudden downpour causes flooding

October 20, 2009 12:23:13 AM PDT

SAN FRANCISCO --

Heavy downpours caused flooding in the Bay Area Monday afternoon. A National Weather Service flood advisory was in effect for San Francisco, San Mateo, Alameda and Contra Costa counties until 5:15 p.m. Rainfall exceeded one inch per hour in some areas.

Flooding caused problems on some North Bay roads as well including Shoreline Highway in Marin County. High water also affected Cesar Chavez at 101 in San Francisco and prompted the closure of the 6th Street onramp to 280. Parts of 80, 580, Richmond Parkway and Cutting Boulevard in Richmond were also affected by high water levels.

Muni service disrupted

Flooding also forced San Francisco's Muni to shut down part of the Powell-Mason cable car line and a large part of the Muni underground. Around 4:15 p.m. light rail service was suspended between the Embarcadero and West Portal stations due to flooding at the Van Ness station. Muni took the Mason portion of the Powell-Mason Cable Car line out of service at 2:35 p.m. Shuttle buses were set up to carry riders during the disruptions.

Just before 5:00 p.m. Muni resumed all services, although trains were continuing to bypass the Van Ness station. At 7:50 p.m. the Van Ness Station was reopened.

Buildings flooded in the Mission District

In the Mission District several homes and businesses flooded and it took all night for the water to drain off. City crews washed the streets and sidewalks with an orange-scented chlorine disinfectant. At 10 p.m. officials reopened Folsom Street.

Around 2:45 p.m. the Folsom and 17th Street area in the Mission District was a mess, as a surge of flood water came blasting out of the sewers and onto the sidewalks. The Public Utilities Commission says San Francisco has a combined sewer system. That means that sewer pipes and runoff combine into one pipe.

"It was really quick and the sewer pipes backed up and both ends of the street had geysers of water about 10 feet high coming from the grate," said Quin Morgan.

Five homes, three apartment garages, and an assortment of businesses including the Stable Cafe and an art gallery, all flooded up to a few feet of water. The concoction of raw sewage and rain water ruined thousands of dollars worth of art. City officials debated evacuating residents because of contamination. Now residents are upset because the sewer system was upgraded in the area about four years ago.

"The size of the pipes were increased to be able to accommodate any type of major rainfall," said San Francisco Public Works Assistant Director Mohammed Nuru.

"All the streets were dug up. They put in a pump station. They were supposed to take care of this problem. I don't think I should be dealing with this crap, and I mean, it's literally crap," said Kevin Thompson, an artist.

San Francisco Public Works Assistant Director Mohammed Nuru says his engineers are trying to figure out why the upgraded sewer system failed.